Circuit interrupter



Aug. 18, 1931. T s 1,819,261

CIRCUIT INTERRUPTER Filed April 12, 1928 ;2- Sheets-Sheet l INVENTORJohn F. Peters MW ATTORNEY Au 18, 1931. F, PETER 1,819,261

CIRCUIT INTERRUPTER Filed April 12, 1928 2 Sheets-Sheet 2 4A lfA /4B Il2 [8 LE I55 I j I /5A' l 4A INVENTOR John F. Peters A'TTORNEY PatentedAug. 18, 1931 UNITED STATES PATENT OFFICE JOHN F. PETERS, OF EDGEWOOD,PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY,A CORPORATION OF PENNSYLVANIA CIRCUIT INTERRUTPTER Application filedApril 12,

denser type insulators, constituting the terminals of a circuitinterrupter arranged to interconnect power systems energized fromseparate sources of alternating current, to furnish stepped-downvoltages corresponding to those of the two systems to an automaticsynchronizing devlce which controls the closure of said circuit breaker.

Other objects of my invention will be clearly apparent from thefollowing description and from the drawings, in which:

Figure 1 is an elevational view in section of a circuit interruptershowing a particular embodimentof my invention,

Figs. 2, 3 and 4 are wiring diagrams of control systems embodying myinvention.

My invention comprises, in general, a circuit interrupter 1 consistingof a tank 2 filled with an insulating fluid 3 in which a bridging member4 for contact members 5 and 6 is suspended. The bridging member 4 issupported on a rod 7 suspended to an operating mechanism 8 that isconnected to an actuating means, not shown. The tank 2 of the circuitinterrupter 1 is enclosed by a cover member 9 that is the means ofsupport for the operating mechanism 8 and for condenser-bushings 11 and12 that constitute a feature of my invention now to be described indetail.

The condenser-bushings 11 and 12 comprise a conductor 13 upon whichalternate layers of insulating and conducting material are wound forminga plurality of condensers. Such an insulatinglbushing is illustrated inReynders Patent 0. 952,467. The ends of the conductors 13 immersed inthe liquid 3 conductively support the contacts 5 and 6 and are connectedat their upper ends to circuits 14 and 15. The outermost conductinglayer 16 is employed to energize the circuits 17 and 18 in a manner thatwill now be described. A circuit 19 has one of its ends connected to thelayer 16, and its other end is connected to ground.

A circuit 19 includes the primary winding 20 of a voltage transformer21, the second- 1928. Serial No. 269,460.

ary winding 22 of which terminates in conductors 23 and 24. Usually,there is connected across the primary winding 20 a spark gap 25, orother well-known protective device, which breaks down upon occurrence ofabnormally high voltage and immediately returns to a non-conductivecondition when normal conditions are restored.

Connected across the conductors 23 and 24 it will usually be desirableto provide a suitable capacitance 26, such as a condenser, and includedin one of said conductors 23 and'24 an inductance 27. The conductors 23and 24 may be of any suitable length and are connected to the respectiveterminals of a suitable relay device that will be described hereinafter.

Preferably, the spark gap 25, the transformer 21, the condenser 26 andthe inductance 27 are disposed within a metallic casing 28 secured tothe wall of casing 1. Under such circumstance the conductors 23 and 24extend thru the wall of casing 28.

Other methods of stepping down and controlling the potential desiredfrom the circuits 17 and 18 may be employed, such as the use ofcondensers in place of the low-voltage transformers but the system abovedescribed is the preferred form. Y

By a proper adjustment of the magnitudes of capacitance 26 andinductance 27, which any skilled electrical engineer will be able tocalculate, and which therefore need not be worked out in detail here, itis possible to arrange that thevoltage between conductors 23 and 24 isin phase with and a predetermined fraction of the voltage between line14 and ground; or alternatively in phase with and a predeterminedfraction of the voltage betwlegen line conductor 14A and line conductor14 Referring particularly to Figure 1, an arrangement is shown in whichthe potential in the circuits 17 and 18 is employed to control asynchronizing device. In this arrangement the power circuit 14 isintended to be connected to the power circuit 15 and this, of course, isto be accomplished only when the alternating voltages of said circuitare in synchronism.

Heretofore, in employing synchronizing indicating means on circuits ofhigh-potential, it has been necessary to supply at each side of thecircuit breaker a potential transformer that is expensive, bulky andthat usually requires extensive high-voltage leads. My invention makesuse of the insulators which must be provided for each circuit breakerterminal to avoid the necessity for such potential transformers. Thearrangement disclosed in Fig. 1 comprises housings 28 of weather proofconstruction in which transformer 21, reactance 27 and condenser 26 areenclosed and which regulates the potential supplied to circuits 17 and18 so that, in each, it is proportional to and in phase with that of theline 14 or 15 with which it is associated.

The circuits 17 and 18 are connected to actuating means 29 and 31respectively of a synchronoscope 32 of any form well known in the artthat records the phase relation of the voltages of the power circuits 14and 15.

For many purposes, such as automatic synchronization, it is notnecessary that the voltage between conductors 23 and 24 be in phase withthe voltage between line 14 and ground; it is sufficient if it has thesame phase relative thereto that the voltage between lines 23 and 24 hasto the voltage between line 15 and ground. Under such conditions ifbushings 11 and 12 are similar units the capacity 26 and inductance 27may be dispensed with and windings 29 and 31 of the synchronizer 32 beconnected directly across the terminals of transformer 21 or evendirectly between the respective layers 16 and the ground.

Figure 2 is a circuit diagram of a circuit interrupter employing asynchronoscope 32 connected in circuit in a manner similar to that shownin Fig. 1. The synchronoscope 32 in Fig. 2 is provided with contactmembers 33 and 34, that, are closed when'the voltages of lines 14 and 15are in phase, thus completing a circuit through a relay 35. The relay 35closes a switch 36 completing a circuit through a closing coil 37 of thecircuit interrupter.

A switch 39, controlling the operation of the circuit interrupter, maybe inserted in the circuit between the contacts 33 and 34 and the relay35. When the circuit interrupter is to be closed, the switch 39 isclosed connecting the relay 35 across the contacts 33 and 34, These willbe closed in the manner already described when the voltages of thecircuits 14 and 15 are in synchronism. The relay may be energized froman auxiliary source of energy such as the battery 38.

The contact 34 is adjustable and may be moved to an advanced position toadvance the closing of relay 35 by a time interval equal to thatrequired to complete the operation of the circuit interrupter. By thismeans the bridging member 4 will be brought into engagement with thecontacts 5 and 6 at the exact time when the voltages of the powercircuits 14 and 15 are in synchronism. This arrangement provides asystem whereby one power circuit may be automatically connected toanother when in exact synchronism by the mere closing of switch 39.

While one form of automatic synchronizer has been shown for controllingthe relay 35, other suitable forms will be obvious to those skilled inthe art.

My invention may also be employed as a means for tripping the circuitinterrupters if desired. In Fig. 3, a separate secondary circuit 17 isenergized by each phase of a three phase system in the above describedmanner. In ig. 3 the power circuit 14 is composed of three phases 14A,14B and 14C,

connected to the bushing 11 of each circuit interrupters A, B and Crespectively. Each circuit 17 is inductively connected to a bushing 11and comprises two conductors 23 and 24. The conductors 23 are connectedtogether by means of the conductor 41.

A relay 42 is connected in series with the circuits 24 of the circuitinterrupters A and C. A relay 43 is connected in series with theconductors 24 of the circuit interrupters A and B. A relay 44 isprovided in series with the circuit 24 of the circuit interrupters B andC.

As the circuit 17 will have the same potential characteristics, as thepotential of the circuit 14, it will thus be seen that a change in thepotential of the power circuit 14 will likewise change the potential inthe circuit 17. Any change of line voltage conditions which could bemade to control relay systems directly such as overvoltage orundervoltage can thus be made to actuate one or all of the relays 42, 43and 44. The relays 42, 43 and 44 must necessarily be of a light burdentype and can be employed to complete the circuit to a second relay thatwill thus be actuated to trip the circuit interrupters A, B and C.

Owing to the limitations of the light burden relays 42, 43 and 44, anarrangement is shown in Fig. 4 in which the burden of the relays may bedouble the amount of those shown in Fig. 3. In this arrangement, each ofthe condenser bushings 11 and 12 of the circuit interrupters A, B and Cis provided with means for supplying the circuits 17 and 18 with apotential as above described. Thus in Figure 4 these circuits are shownconnected in parallel to the relays 42, 43 and 44 and this arrangementprovides twice as great a current to such relays as does the systemshown in Fig. 3.

In Fig. 4 the power circuit 14 is connected to the load circuit 15 in amanner such that the load side 15 will be deenergized upon the openingof the circuit interrupters A, B and C. It is found desirable to providea switch 45 between each of the circuits 17 and i operate and to installas the energy in the 18 so connected to the operating mechanism of thecircuit interrupters that it is opened when the circuit interrupteropens. The

opening of the switch prevents any feed- 5 back of power through thepower circuit 14, the secondary circuits 17 and 18 to the load circuit15.-

The. circuit interrupter A in Figure 4 can also be employed forsynchronizing when connecting two proper circuits 14 and 15 shown inFigs. 1 and 2 if it is provided with the same control circuits thesefigures show.

It will thus be seen that I have provided a source of control "for theoperation of a circuit interrupter that is very economical to circuit isprovided from equipment already in the field, that is, from thecondenser bushing of circuit interrupters. My system is also novel inproviding a circuit for actuating a synchronoscope that automaticallyactuates a circuit to energize the closing means of a circuitinterrupter when the two power circuits are in synchronism.

My method is further novel in employing the induced potential from acondenser bushing of a circuit interrupter to operate meters to indicatethe potential characteristics of the main circuit and to operate relaysfor the control of the said circuit interrupter.

It is to be understood that such changes in the form arrangements andconnections of the component parts of my invention may be made as shallfall'within the scope of the appended claims.

I claim as my invention:

1. Apparatus for connecting together two separately-energized sectionsof a high-tension alternating-current line when they are in synchronism,consisting of a switch for connecting the sections having two terminalseach connected with a separate one of said line-sections, alow-potential terminal associated with each switch terminal and derivingpotential therefrom, and a synchronismresponsive device connected withbothof said low-potential terminals to indicate when the sections are insynchronism and the switch can be closed.

2. An electric switch for connecting together two high tensionline-sections when they are in synchronism with each other, saidswitchhaving two insulated stationary terminals each adapted for connectionwith a separate one of the two line sections, and a movable switchmember for connecting said terminals, each of said stationary terminalsconstituting a condenser having an insulated low-potential terminal,both of said low-potential terminals adapted for connection withsynchronism-responsive a paratus.

3. An electric switch or connecting to- 'gether two high-tensionline-sections when they are in synchronism with each other, said 3switch having section terminals, and a movable member for bridging saidterminals, and also having low-potential terminals, the potential ofeach of which is a function of the potential of a separate one of thesection terminals.

4:. An electric switch for connecting together two high-tensionline-sections when they are in synchronism with each other, said switchhaving two insulated switch terminals each connected with a separate oneof the line sections, both insulated terminals constitutcasing for saidswitch having high-tensionterminals thereon for connection to saidlines, respectively, means for deriving a potential from each of saidhigh-tension terminals proportional to, and substantially in phase with,the voltage of the respective alternating-current lines, asynchronism-responsive device,

and electrical connections for energizing said detl'ice in accordancewith'said derived potentia s.

6. Apparatus for connecting together two separately-energized sectionsof a high-tension alternating-current line when they are in synchronism,consisting of a switch for connecting the sections having two terminalseach connected with a separate one of said line-sections, meansincluding a low-potential terminal associated with each switch terminalfor deriving potentials proportional to, and substantially in phasewith, the potentials of the respective line-sections, asynchronism-responsive device and means for energizing said device inaccordance with said derived potentials.

7. In combination with the terminals of two separately-energizedhigh-tension alternating-current lines, a synchronism-responsive deviceassociated with said terminals, and means for energizing saiddevice fromsaid terminals including a low-tension terminal associated with eachhigh-tension terminal for energization capacitatively therefrom,electrical circuits operatively connecting said low-tension terminalsand said synchronism-responsive device and means in each of saidcircuits for establishing a condition of substantial resonance Withrespect to the frequency of the power traversing the respectivehigh-tension lines.

In testimony whereof I have hereunto subscribed my name this 11th day ofApril, 1928.

JOHN F. PETERS.

